A conventional circuit-board is described in the publication, IPC Standard 1985, "Proposal Qualification and Performance Specification for Metal Core Boards" of the Institute for Interconnecting and Packaging Electronic Circuits, pp. 1-5. The conventional circuit-board comprises three parts: an internal metal core plate as the heat sink and two plastic plates arranged on both sides of the metal core plate and bonded to it. On their sides facing away from the metal core plate, the plastic plates are copper-clad and provided with a lead-tin layer in the conventional way for mounting electronic components. The metal core plate forms a plate-shaped heat sink by which the heat generated by the electronic components can be properly dissipated. However, the dissipation of heat with the conventional circuit-board is not optimal because heat transfer from the plastic plates to the plate-shaped heat sink is prevented by the adhesive layers.